1. Field of the Invention
This invention relates to a new class of chemical compounds and compositions useful in providing efficient bleaching of textiles over a wide range of washing temperatures, but especially at low temperatures (less than about 50.degree. C.). The present invention provides a new compound for use in detergent bleaches or as laundry additives, said compound having the general formula ##STR2## wherein R is C.sub.1-20 linear or branched alkyl, alkylethoxylated, cycloalkyl, aryl, substituted aryl; R' and R" are independently H, C.sub.1-20 alkyl, aryl, C.sub.1-20 alkylaryl, substituted aryl, and NR.sub.3.sup.a+, wherein R.sup.a is C.sub.1-30 alkyl; and L is essentially any useful leaving group which can be displaced in a peroxygen bleaching solution by perhydroxide anion. It is most preferred that R' and R" are both H, and thus R'--C--R" is methylene. The alpha hydroxy substituted carbon plus the carbonyl form the glycolate group. When the precursor is combined with a source of hydrogen peroxide, this reaction results in the formation of a peracid, and, under certain circumstances, uniquely to this invention, in the formation of a mixture of peracids. The structure and reactivity of the compounds are unique in that higher yields of peracids can be obtained across a broader pH range and temperature than conventional fatty acid based bleach activators.
2. Brief Description of the Prior Art
Numerous substances have been disclosed in the art as effective bleach activators. British Patent Specification No. 1,147,871, Boldingh et al, describes bleaching and detergent compositions containing an inorganic persalt and acyloxyalkyl or acyl benzene sulfonates. It is claimed that such esters provide improved bleaching temperatures below 70.degree. C. when compared to compositions using the persalt alone.
These activators are represented by the formula: ##STR3## wherein X=branched or straight chain alkyl or acyl radical containing 6-17 carbon atoms; R=H or alkyl radical having 1-7 carbon atoms; and M=an alkali metal, or ammonium radical.
Chung et. al., U.S. Pat. No. 4,412,934, discloses bleaching compositions containing a peroxygen bleaching compound and a bleach activator of the general formula ##STR4## wherein R is an alkyl group containing from about 5 to about 18 carbon atoms; L is a leaving group, the conjugate acid of which has a pK.sub.a in the range of about 6 to about 13. Chung et al focuses on alkanoyloxy benzene sulfonates, which have been previously disclosed in G.B. No. 864,798, Hampson et al.
Thompson et. al, U.S. Pat. No. 4,483,778, discloses bleach activators of the structure ##STR5## wherein R is C.sub.4-14 alkyl, R.sup.1 is H or C.sub.1-3 alkyl, X is --Cl, --OCH.sub.3, or --OCH.sub.2 CH.sub.3, and L is a leaving group whose conjugate acid has a pK.sub.a of 4-30. Unlike the apparently crowded alpha carbon in the Thompson et al compound, the present invention has non-hindered enhanced perhydrolytic reactivity.
EP No. 166 571, Hardy et. al, discloses the use of a bleach activator compound of the formula [RX].sub.m AL, wherein R is hydrocarbyl, C.sub.6-20 alkylsubstituted aryl, or alkoxylated hydrocarbyl; X is O, SO.sub.2, N(R.sup.1).sub.2, (R.sup.1)P.fwdarw.O or (R.sup.1)N.fwdarw.O, wherein for m=1, A includes ##STR6## and L can be oxybenzene sulfonate.
E.P. No. 170 368, Burns et al, discloses the use of amide esters of the formula ##STR7## wherein R.sup.1 and R.sup.2 are alkyl(ene) aryl(ene) or alkylaryl(ene) with 1-14 carbon atoms and R.sup.5 is H, an alkyl, aryl, or alkylaryl group with 1-10 carbon atoms.